Search Publications
Effects of a solar wind dynamic pressure increase in the magnetosphere and in the ionosphere
Milan, S. E.; Kauristie, K.; Amm, O. +4 more
On 17 July 2005, an earthward bound north-south oriented magnetic cloud and its sheath were observed by the ACE, SoHO, and Wind solar wind monitors. A steplike increase of the solar wind dynamic pressure during northward interplanetary magnetic field conditions was related to the leading edge of the sheath. A timing analysis between the three spac…
Analysis of Spatial Structure of the Spica H II Region
Park, J. -W.; Min, K. -W.; Edelstein, J. +2 more
Far ultraviolet (FUV) spectral images of the Spica H II region are first presented here for the Si II* λ1533.4 and Al II λ1670.8 lines and then compared with the optical Hα image. The Hα and Si II* images show enhanced emissions in the southern part of the H II region where H I density increases outward. This high density region, which we identify…
Multiple Weak Deflections in Galaxy-Galaxy Lensing
Brainerd, Tereasa G.
The frequency and effects of multiple weak deflections in galaxy-galaxy lensing are investigated via Monte Carlo simulations. The lenses in the simulations are galaxies with known redshifts and known rest-frame blue luminosities. The frequency of multiple deflections above a given threshold shear value is quantified for discrete source redshifts, …
Ellipsoidal primary of the RS CVn binary ζ Andromedae . Investigation using high-resolution spectroscopy and optical interferometry
Strassmeier, K. G.; Korhonen, H.; Wittkowski, M. +3 more
Aims: We have obtained high-resolution spectroscopy, optical interferometry, and long-term broad band photometry of the ellipsoidal primary of the RS CVn-type binary system ζ And. These observations are used to obtain fundamental stellar parameters and to study surface structures and their temporal evolution.
Methods: Temperature maps of…
Asymmetry in the Jovian auroral Lyman-α line profile due to thermospheric high-speed flow
Chaufray, J. -Y.; Clarke, J. T.; Waite, J. H. +1 more
The presence of a fast wind in the auroral region atmosphere of Jupiter has been detected from the Doppler shift in near-IR observations of H3+ emissions. The Doppler effect also modifies auroral resonance emission line shapes. We present a new radiative transfer equation for the hydrogen Lyman-α line in the presence of a hor…
Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT
Aigrain, S.; Auvergne, M.; Schneider, J. +19 more
Context. The present work deals with the detection of phase changes in an exoplanetary system. HD 46375 is a solar analog known to host a non-transiting Saturn-mass exoplanet with a 3.0236 day period. It was observed by the CoRoT satellite for 34 days during the fall of 2008.
Aims: We attempt to identify at optical wavelengths, the changing p…
Two-dimensional time-dependent model of the transport of minor species in the Venus night side upper atmosphere
Gérard, Jean-Claude; Collet, Arnaud; Cox, Cédric
We present a numerical tool developed to quantify the role of processes controlling the spatio-temporal distribution of the NO ultraviolet and O2(Δg1) infrared nightglows in the Venus night side upper atmosphere, observed with the VIRTIS and SPICAV instruments on board Venus Express. This numerical tool consists in a two-dimensional che…
Recovery of time evolution of Grad-Shafranov equilibria from single-spacecraft data: Benchmarking and application to a flux transfer event
Hasegawa, Hiroshi; Sonnerup, Bengt U. Ã. -.; Nakamura, Takuma K. M.
First results are presented of a method, developed by Sonnerup and Hasegawa (2010), for analyzing time evolution of magnetohydrostatic Grad-Shafranov (GS) equilibria, using data recorded by an observing probe as it traverses a quasi-static, two-dimensional (2D), magnetic-field/plasma structure. The method recovers spatial initial values used in th…
Extinction and Distance to Anomalous X-ray Pulsars from X-ray Scattering Halos
van Kerkwijk, M. H.; Rivera-Ingraham, A.
We analyze the X-ray scattering halos around three Galactic Anomalous X-ray Pulsars in order to constrain the distance and the optical extinction of each source. We obtain surface brightness distributions from EPIC-pn data obtained with XMM-Newton, compare the profiles of different sources, and fit them with a model based on the standard theory of…
The Alfvén edge in asymmetric reconnection
André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +1 more
We show that in the case of magnetic reconnection where the Alfvén velocity is much higher in the plasma on one side of the current sheet than the other, an Alfvén edge is formed. This edge is located between the electron and ion edges on the high Alfvén velocity side of the current sheet. The Alfvén edge forms because the Alfvén wave generated ne…